Separation of various hydrocarbons, polluted with residues to a greater or lesser degree, from an aqueous medium raises technical problems which are often difficult to resolve. Numerous solutions have been proposed for each individual case to which they must be adapted. For example, in the attempt to remove crude oils spilled at sea, use has been made of either physical or mechanical processes for removing the "black tide" layer, or of chemical processes intended to cause coagulation and suspension of hydrocarbon particles which are then separated to a greater or lesser degree from the water by various means.
Another source of such hydroorganic media which must be separated, very frequent in practice, relates to the degreasing or dewaxing of various materials, such as, in particular, automobiles (buses, trucks, and passenger cars), and machine tools. Such degreasing or dewaxing processes take place in industrial plants, such as refineries and textile dyeing mills, and in the food industry, etc. In general, machines capable of spraying jets of water or steam at a pressure of several bars are used to clean off the film of monomer or polymer hydrocarbon compounds (included under the general term "wax") which temporarily protects these materials during storage and/or transport. A small quantity of solvent is introduced into the water spray (kerosene or the like) to facilitate elimination of all traces of oil or grease.
The aforementioned processes, particularly water spraying, are indeed very effective, but their implementation gives rise to enormous quantities of aqueous liquids polluted by large fractions of organic compounds and various wastes and residues. Very often this waste water is discharged untreated into the sewer which causes dangerous contamination and pollution of water courses, rivers, and underground water. Moreover, the treatment required to separate the hydrocarbon fraction calls upon techniques which are generally too complex and cumbersome for many industrialists.